JPH1110968A - Hot melt ink-jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent image quality from being deteriorated by quickly cooling a heated medium P to be printed after the medium is printed with a hot melt ink. SOLUTION: At the lower side of a transfer route than a main platen 26 having a main heater 26a at the side of a rear face, a second suction port 37 is formed between a supporting frame body 30 supporting a cooling platen 27 via a first suction port 36 and the cooling platen 27. A paper discharge roller 28 is set at the lower side than the second suction port 37. A cooling air introduced from a paper discharge port of a printer by a suction fan 35 arranged below the supporting frame body 30 is sucked through the second suction port 37 to hold the cooling platen 27 at low temperatures during a printing operation, thereby enhancing cooling efficiency of a medium P after the medium is printed by jetting of a hot melt ink from a nozzle head 13 at a surface of the main platen 26. When the printing operation is kept standby, the cooling air is sucked also from the first suction port 36, so that the main platen 26 is speedily controlled to change temperatures.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer using hot melt ink, and more particularly, to a structure for heating and cooling a recording medium in the printer.

[0002]

2. Description of the Related Art Conventionally, in this type of printer, a recording head section comprising a nozzle head having a number of nozzles, an ink melting section having a heater, and a hopper section for receiving solid ink pellets is mounted on a carriage. The ink jet (hot melt ink) is ejected from the nozzles of the nozzle head while moving the carriage in a direction (main scanning direction) orthogonal to the transport direction of the recording medium such as paper, and the surface of the recording medium is ejected. It is configured to print characters, figures, etc.

When a drop of this type of hot-melt ink adheres to the surface of a recording medium having a low temperature, the droplet immediately solidifies on the surface, so-called ink fixability is poor, and the ink droplet There is a problem that a phenomenon such as dropping of a printed portion due to dropping occurs and good image quality cannot be obtained. On the other hand, if hot melt ink is ejected from the nozzle head onto the recording medium which has been preliminarily heated and the temperature has been raised in advance, the fixing performance of the ink will be improved. When the printed hot-melt ink is not solidified when the paper is fed between the printed recording media in between, the ink is transferred to a pinch roller or the like (image is taken), which also deteriorates the image quality.

Therefore, in the prior art, a heater is provided on the back side of the platen arranged opposite to the nozzle head to increase the temperature of the recording medium in contact with and supported by the platen, while discharging the paper from the platen. The transport distance between the roller and the pinch roller to the paper discharge section is set to be large, and while moving over the long transport distance, the printed recording medium is cooled to complete the solidification of the hot melt ink. I was

[0005]

However, if the transport distance is set to be long, there is a problem that the dimensions of the entire printer become large. In addition, if the conveying speed of the printed recording medium is increased, the time required for moving from the printing to the paper discharge roller (cooling time) is substantially shortened. There is also a problem that image quality cannot be obtained, and therefore high-speed printing cannot be performed.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a compact hot-melt ink jet printer which does not degrade image quality even at high speed printing processing. Is what you do.

[0007]

According to a first aspect of the present invention, there is provided a hot-melt ink-jet printer according to the first aspect of the present invention, wherein a recording medium is provided on a surface of a main platen facing a nozzle head for ejecting hot-melt ink. The recording medium is supported by the main platen, the hot melt ink is ejected from the nozzle head to the surface of the recording medium to form an image, and then discharged via a discharge roller while being cooled. In a hot-melt ink-jet printer configured to print on paper, a cooling platen is provided downstream of the main platen in the conveyance direction.

According to a second aspect of the present invention, there is provided a hot-melt ink-jet printer which conveys a recording medium along a surface of a main platen facing a nozzle head for ejecting hot-melt ink, and performs recording on the main platen. A hot-melt ink-jet printer configured to support a medium, eject a hot-melt ink from the nozzle head to the surface of the recording medium, form an image, and then discharge the sheet via a discharge roller while cooling the sheet. A suction port and a cooling platen are provided downstream of the main platen in the conveyance direction, and cooling air is introduced from the sheet discharge port side to the cooling platen by a suction fan disposed on the back side of the platens. Things.

According to a third aspect of the present invention, there is provided a hot-melt ink-jet printer which transports a recording medium along a surface of a main platen facing a nozzle head for ejecting hot-melt ink, and at least supplies the medium to the main platen. The recording medium is supported from the back side while being heated by heating, the hot melt ink is ejected from the nozzle head to the surface of the recording medium to form an image, and then discharged via a discharge roller while being cooled. In the hot-melt ink-jet printer configured as described above, a suction port and a cooling platen are provided on the transport downstream side of the main platen having the main heating means on the back side, and a suction fan arranged on the back side of both platens, The cooling air is introduced from the discharge port side toward the cooling platen.

[0010] Further, the invention according to claim 4 is based on claim 2.
4. The hot melt ink jet printer according to claim 3, wherein the suction port intersects the conveyance path on the upstream side of the cooling platen and conveys, and the first suction port can be closed by a recording medium after printing. On the downstream side of the platen, a second suction port for sucking cooling air is provided on the back side of the cooling platen.

According to a fifth aspect of the present invention, in the hot melt ink jet printer according to the fourth aspect, a heat insulating partition is provided at the first suction port so as to separate a main platen and a cooling platen. And it is comprised so that cooling air may pass along both surfaces of this heat insulation partition. According to a sixth aspect of the present invention, in the hot melt inkjet printer according to any one of the second to fifth aspects, the suction fan rotates at a high speed during a printing operation and rotates at a low speed during a printing operation standby. The switching operation is performed as described above.

According to a seventh aspect of the present invention, in the hot melt inkjet printer according to any one of the second to sixth aspects, the supporting member for supporting the back side of the main platen and the back side of the cooling platen includes: A flow passage for introducing cooling air from the suction port in the suction fan direction is formed.

[0013]

Next, embodiments of the present invention will be described. FIG. 1 is a perspective view of a hot melt ink jet printer according to the present invention, FIG. 2 is a side sectional view of the printer, FIG. 3 is a schematic plan view of a printing unit, and FIG. As shown in FIGS. 1 and 2, on the rear side of the upper surface of the main body case 1a of the printer 1, cut paper as a recording medium and transparent paper such as a transparent film for an overhead projector are stacked in a stacked state. A plurality of paper feed units 2 and 3 for setting are detachably mounted. As shown in FIG. 1, an operation panel unit 4 having various operation switches is provided on the right side of the upper surface of the main body case 1a.
In addition, a paper outlet 5 for discharging the recording medium P after printing is opened on the front surface of the main body case 1a, and the paper is discharged onto a paper discharge tray 6.

With the openable and closable outer cover 7 shown in FIG.
The upper surface of the central opening 1b on the upper surface of the main body case 1a can be covered. Further, on the left side of the central opening 1b, yellow (Y) for a color ink jet printer,
An ink case 8 having a plurality of storage grooves 8a capable of storing respective magenta (M), cyan (C), and black (K) ink pellets (not shown) in a row is detachably mounted. The upper surface of the ink case can be opened by a cover body 9. Further, a transparent cover 10 (with a large number of exhaust holes 10a) fixed to the right side of an ink case 8 as an ink supply portion and protruding sideways can cover the right side of the central opening 1b.

As shown in FIG. 2 to FIG.
The recording head unit 11 mounted on the
A panel heater 14a which supports the nozzle head 13 on the lower surface side, and reciprocates ink passages and heats these passages.
On the back side, and a heater 15 on the back side
a, a melting hopper 16 also having a heater 16a on the back side, a lid panel 17 covering the back side of the front panel 14, the nozzle head 1
3 includes a control board for controlling a piezoelectric element for executing ink ejection, and a relay section 18 provided with a control board for controlling each heater.

The carriage 12 is mounted on the main body case 1a.
Inside, it is configured to be able to reciprocate along a guide mechanism 19 and a guide rail 20 in the sub-scanning direction along with a traveling mechanism (not shown). An ink supply mechanism (not shown) is arranged below the front end of the ink case 8.
When the printing operation is performed and the ink is consumed, the remaining amount of the hot melt ink of the predetermined color in the ink tank 15 decreases, and when a sensor (not shown) detects that the ink has run out,
The carriage 12 is moved so that the portion of the melt hopper 16 where the ink has run out is located below the outlet of the portion where the ink pellet of the corresponding color is stored in the ink case 8, and the ink supply is performed. The driving unit of the mechanism operates to drop solid ink pellets of a predetermined color at room temperature into the melting hopper 16. On the other hand, at the right end in the main body case 1a of the printer 1, hot melt ink is ejected from the nozzles of the nozzle head 13 onto the trial roll paper in a state where the carriage 12 is located at the corresponding position, thereby performing normal printing. A maintenance operation unit 21 for preventing nozzle clogging or the like during operation is disposed.

At the lower end of each paper feed unit 2, 3,
As shown in FIG. 2, a half-moon-shaped (D-shaped) sheet feeding roller 22 is provided.
a, 22b, and the recording media P stacked on each of the paper feed units 2, 3 or the manual recording media P from the manual feed trays 2a, 3a on the upper surface of each paper feed unit 2, 3.
To the transport path 29. As shown in FIG. 4, the transport path 29 includes a pair of registration rollers 23a,
23b, pre-heat platen 24, transport roller 25 and pinch roller 25a, main platen 26, cooling platen 27, paper discharge roller 28 and pinch roller 28a, paper discharge port 5
4 and 6, the preheat platen 24 and the main platen 2 are arranged as shown in FIGS.
6, a pre-heater 24a as a pre-heating means and a main heater 26 as a main heating means disposed on each back side.
At a, the recording medium P is heated from its back surface. The surface temperature of the preheat platen 24 is desirably set slightly higher than the surface temperature of the main platen 26.

The preheat platen 24, the main platen 26, and the cooling platen 27 are preferably made of a metal material such as aluminum having a high thermal conductivity.
At least the main platen 26 and the cooling platen 2
Reference numeral 7 is formed in a convex curved shape such as a circumferential surface with a radius R such that the front surface (the side facing the back surface of the recording medium P) approaches the nozzle head 13 side. As shown in the embodiment, the preheat platen 24 and the main platen 26 may be formed integrally. The preheat platen 24 may also be formed in a convex curved shape such as a circumferential surface having a radius R.

With these constructions, the conveying roller 25 and the pinch roller 25a pinch the conveyance upstream of the recording medium P, and the conveyance downstream of the recording medium P discharge rollers 28.
When the recording medium P is conveyed while being tensioned between the preheat platen 24 and the main platen 26, the cooling platen 27
The entire back surface of the recording medium P is uniformly and contact-supported by the convex curved surface formed over the entire surface, so that heat transfer (heating) to the recording medium P in the heating area and the cooling area (the cooling platen 27 Heat absorption (cooling) on the surface or the like can be efficiently performed.

Polyether imide, polyamide imide,
A main platen 26 (preheat platen 24) supported by a support frame 30 made of a heat-resistant synthetic resin such as polyimide.
) Includes protrusions 3 on both left and right ends with screws 31.
0a (see FIG. 6A). Further, the cooling platen 27 disposed in the lower portion of the support frame 30 is attached to the projection 30b so as not to fall off by screws 32 fitted in the recesses 27a at both left and right end portions, and FIG.
As shown in (a), the minute distance H1 (0.1 mm in the embodiment)
Up to about 0.2 mm). Longitudinal direction of this cooling platen 27 (moving direction of carriage 12)
The back side of the middle part etc. along the bottom and the bottom plate 3 of the support frame 30
A biasing spring 33 such as a coil spring is interposed between the projection 30d and the projection 30d protruding from 0c, and the cooling platen 27 is projected and biased toward the nozzle head 13 (see FIG. 6B).

Accordingly, the conveying roller 25 and the pinch roller 25a pinch the conveying upstream side of the recording medium P, and the conveying downstream side of the recording medium P is pinched by the paper discharging roller 28 and the pinch roller 28a. When the medium P is conveyed while applying tension, the entire surface of the cooling platen 27 along the conveyance direction can be pressed exactly against the back surface of the recording medium P, and the recording medium P moves from the recording medium P to the cooling platen 27 side. Heat transfer can be performed efficiently. The rotation speed of the discharge roller 28 is set to be faster than the rotation speed of the transport roller 25.
The pinching force between the sheet discharging roller 28 and the pinch roller 28a is set to be weaker than the pinching force between the transport roller 25 and the pinch roller 25a, so that the sheet discharging roller 28 slips by the speed difference. . However, even if the holding force on the paper discharge roller 28 side is set to be weak, the recording medium P does not rise from the transport path due to the urging force of the cooling platen 27 (the elastic force of the urging spring 33). Needless to say, it has a holding force of a degree that can be suppressed. Further, as shown in FIG.
6 and the pre-baffle 44 pressing the free end against the surface of the pre-heat platen 24 to further ensure the pressing action of the recording medium P.
44 is made of a heat-resistant synthetic resin material such as a polyimide film having heat resistance and elasticity.

In the present invention, the main platen 2 having a main heater 26a as a main heating means on the back side is provided.
A suction port and a cooling platen 27 are provided on the downstream side of the conveyance from the suction port 6, and the cooling fan 35 arranged on the back side of the platens 26, 27 cools the cooling platen 27 from the sheet discharge port 5 side toward the cooling platen 27. It is configured to introduce air. That is, as shown in FIG. 2, FIG. 4, FIG. 6A and FIG. 6B, the suction fan 35 is disposed in the frame 34 disposed below the transport path 29, and The support frame 30 is attached to a position near the upper front of the support frame 30. By disposing a predetermined distance between the transport downstream end of the main platen 26 fixed to the support frame 30 and the transport upstream end of the cooling platen 27, the second port as one of the suction ports is provided. One suction port 36 is formed longitudinally along the sub-scanning direction of the carriage 13. This first suction port 36
, A long and thin heat insulating partition wall 38 made of a heat-resistant synthetic resin is provided so as to thermally isolate the downstream end of the main platen 26 from the transport and the upstream end of the cooling platen 27. .

On the other hand, another suction port is provided between the lower surface of the downstream end portion of the cooling platen 27 and the wall plate 30e of the support frame 30 at appropriate intervals along the sub-scanning direction of the carriage 13. And a plurality of second suction ports 37 are formed.
The second suction port 37 is disposed between the paper discharge rollers 28 having an appropriate length (for example, only the support shaft 28b of the paper discharge rollers 28).
Are formed at a plurality of locations.

An air passage 39 communicating with the first suction port 36 and the second suction port 37 and guiding cooling air to the suction fan 35 is formed in the bottom plate 30c of the support frame 30 (see FIG. 2). FIG. 6A and FIG. 6B). further,
Exhaust ports 40 and 41 are opened on the rear surface and the like of the frame 34, and a power supply substrate 42 is disposed in the frame 34 between the exhaust ports 40 and 41 and the suction fan 35 (FIG. 2). reference). A light transmission type for discriminating the type of the recording medium P between the plain paper and the transparent paper such as a transparent film for an overhead projector is provided in a transport path 29 between the registration roller pair 23b and the preheat platen 24. And outputs a detection signal for control such as a change in the temperature condition of the heater as described later.

Next, a control system in the hot-melt ink jet printer having the above configuration will be described with reference to a block diagram shown in FIG. The CPU 50 includes a ROM 51
According to various control programs stored in advance in
Based on the print data sent from the host computer, it executes various arithmetic and control operations necessary for printing a color image, and is for driving the nozzle head 13 based on the print data. A print head drive circuit 62, a carriage drive circuit 63 for driving a carriage motor 60 for reciprocating the carriage 13 in the main scanning direction, a heater control circuit 64 for controlling the energization of the pre-heater 24a and the main heater 26a,
A fan driving circuit 65 for driving the suction fan (cooling fan) 35; rotating the transport roller 25 and the discharge roller 28 in the paper transport direction during normal rotation; and selecting an ink supply mechanism or a maintenance mechanism during reverse rotation. The conveyance system drive circuit 66 for driving the paper feed motor 61 as one drive source for selectively operating the recording medium P by selectively operating one of the paper feed rollers 22a and 22b. A paper feed system drive circuit 67 for driving a paper feed solenoid 68 for sending out to the path is connected to each other, and a pre-thermistor 69 for detecting the temperature of the pre-heat platen 24 and the main platen 26
A predetermined control signal is output to the heater control circuit 64 or the fan drive circuit 65 based on various detection signals and the like input from the main thermistor 70 for detecting the temperature of the optical sensor 45 and the optical sensor 45. It is configured to be.

In the ROM 51, in addition to storing various control programs, the control temperature of the preheat platen 24 or the main platen 26 is stored and set according to the type of the recording medium P and the printing resolution. R
The AM 52 is temporarily used as a work area for temporarily storing print data sent from the host computer and executing various control operations.

Next, the cooling operation of this configuration will be described. When a power switch (not shown) of the printer 1 is turned on, a printing operation standby state is established, a current is conducted to the pre-heater 24a and the main heater 26a, and preparation for heating is started. , The suction fan 35 also rotates. As a result, in the printing operation standby state, the first
Since the suction port 36 is not closed, the cooling air taken in from the paper discharge port 5 is guided from the discharge side conveyance path 29 to the downstream side of the conveyance of the cooling platen 27, and the first suction port 36 and From both suction ports of the second suction port 37, the support frame 3
4, the air blown out through the suction fan 35 in the frame 34 flows along the surface of the power supply board 42 to take heat, and is exhausted to the outside of the main body case 1a through the exhaust ports 40 and 41. Is done. In the printing operation standby state, the rotation speed of the suction fan 35 is set lower than during the printing operation, and the pre-heater 24a and the main heater 26a
To reduce power consumption.

Next, when the printing operation starts, the preheater 2
4a and a predetermined electric power to the main heater 26a,
The preheat platen 24 and the main platen 26 are maintained at a predetermined temperature. Then, when the type of the recording medium P is selected and a paper feeding command is issued, a predetermined paper feeding roller 22a or 22b is driven to rotate, and the leading end of the recording medium P to be printed is once shifted by the registration rollers 23a or 23b. After stopping at the position and adjusting the posture of the front edge in the conveyance direction, the conveyance roller 2
5 is conveyed.

The recording medium P is pressed against the surface of the pre-heat platen 24 by a pre-baffle 44 as a resilient piece, receives a preheating action, and then pressed against the surface of the main platen 26 by a main baffle 43. While receiving this heating effect. Further, when the leading end of the recording medium P closes the first suction port 36, the back surface of the recording medium P does not rise from the convex curved surface of the main platen 26 due to the suction effect. Can reliably receive the heating action.

In this manner, the recording medium P conveyed while being in contact with and supported by the surfaces of the platens 24 and 26 is heated to a predetermined temperature, and is ejected from the nozzle head 13 at a location facing the main platen 26. Make it easy for hot melt ink to adhere. Next, when the recording medium P is nipped at the location of the paper discharge roller 28, the first suction port 36 is closed by the recording medium P, and there is almost no inflow of air from this location, and the cooling platen A large amount of cooling air is sucked into the support frame 34 from the second suction port 37 on the back surface side of the support frame 27.

The printed portion of the recording medium P sandwiched between the position of the transport roller 25 and the position of the paper discharge roller 28 is a portion of the cooling platen 27 which is urged to protrude via an urging spring 33. Since it is in close contact with the convex curved surface (see FIG. 6B), the entire surface of the cooling platen 27 along the transport direction can be pressed exactly against the back surface of the recording medium P, and Cooling platen 27
Heat transfer to the side can be performed efficiently.

As a result, the temperature of the cooling platen 27 is rapidly lowered, and heat can be quickly removed from the recording medium P discharged in close contact with the surface thereof. The attached hot melt ink solidifies even if the transport distance is short until reaching the holding portion 28a, or if the printing speed is increased to increase the main scanning direction speed (transport speed) of the recording medium P. And the discharge roller 2
8, the image quality is not deteriorated because it is not reflected on the surface of the pin roller 28a, and the fixability of the printed portion is improved even in high-speed printing processing, so that the image quality does not deteriorate.

The first suction port 36 is provided with a heat insulating partition 3.
By disposing the cooling platen 8, the cooling platen 2, such as heat radiation from the main platen 26, which must maintain a high temperature
7, the temperature of the cooling platen 27 can be reliably kept low. In the embodiment, when printing on plain paper, the surface temperature of the main platen 26 is set to 68 ° C. and the resolution is set to 60 dpi at a resolution of 300 dpi.
When printing on a transparent film for overhead projects with a surface temperature of 65 ° C at 0 dpi, a resolution of 60
The surface temperature is set to 80 ° C. at 0 dpi. As described above, when it is desired to change the type of the recording medium P and the printing conditions, the temperature of the main platen 26 during printing must also be rapidly changed.

For example, when changing the above conditions or the like, particularly when it is desired to rapidly lower the temperature of the main platen 26, the cooling air sucked in from the first suction port 36 supplies the main platen 26 with the cooling air. It is necessary to increase the cooling effect. Therefore, when the first suction port 36 is not closed by the recording medium P, the rotation speed of the suction fan 35 is increased, and the heat insulating partition 38 is disposed in the first suction port 36. , Main platen 26
In the narrow flow path between the downstream edge of the conveyance and the heat insulating partition wall 38, the flow velocity of the sucked air is increased, and the cooling effect on the main platen 26 can be improved. By making the shape of the gap between the main platen 26 and the heat insulating partition 38 narrower on the suction inlet side and wider on the inner side of the support frame 34, the cooling effect can be further improved.

In the above-described embodiment, the preheat platen 24 is brought into contact with the back side of the recording medium P in the same manner as the main platen 26 to perform preliminary heating. It is not necessary to make contact with the recording medium P. For example, the recording medium P may be brought into contact with the front side (the side to which ink adheres), or at least two preheat platens are provided so as to come into contact with both front and back surfaces. May be. In particular, when a concave pre-heated platen is provided so as to be in contact with the surface side of the recording medium P, the surface on which the ink adheres can be efficiently heated.

The preheat platen 24 does not necessarily have to have a width equal to or longer than the width of the recording medium P in the main scanning direction. In the case of a preheat platen having a slightly shorter width in the main scanning direction, or a case where the preheating platen is intermittently installed in the main scanning direction, the effect of the preheating is sufficient. Can be played.

[0037]

As described above in detail, in the hot melt ink jet printer according to the first aspect of the present invention, the recording medium is arranged along the surface of the main platen facing the nozzle head for ejecting the hot melt ink. The main platen conveys the recording medium, the hot melt ink is ejected from the nozzle head onto the surface of the recording medium to form an image, and then the sheet is discharged via a discharge roller while being cooled. In the hot melt ink jet printer configured as described above, a cooling platen is provided downstream of the main platen in the conveyance.

According to this configuration, since the cooling platen comes into contact with the back surface of the printed recording medium, the temperature of the recording medium can be efficiently and quickly reduced. Also, the ink is not transferred on the discharge roller side, and the image quality is not degraded. Further, by providing the cooling platen, the distance from the location of the main platen, which is a printing unit, to the paper discharge roller can be reduced, and the printer can be designed to be compact.

According to a second aspect of the present invention, there is provided a hot-melt ink jet printer which conveys a recording medium along a surface of a main platen facing a nozzle head for ejecting hot-melt ink, and performs recording on the main platen. A hot-melt ink-jet printer configured to support a medium, eject a hot-melt ink from the nozzle head to the surface of the recording medium, form an image, and then discharge the sheet via a discharge roller while cooling the sheet. A suction port and a cooling platen are provided downstream of the main platen in the conveyance direction, and cooling air is introduced from the sheet discharge port side to the cooling platen by a suction fan arranged on the back side of the platens. Things.

According to this configuration, the cooling air taken in from the paper discharge port side is sucked by the suction fan located on the back side of the main platen and the cooling platen, which is located downstream of the main platen in the conveyance direction. As a result of being sucked into the mouth, the cooling platen can be cooled in a state in which heat from the main platen side, which is the leeward side, does not heat the cooling air flowing toward the cooling platen, and the cooling effect can be improved. Since the cooling platen contacts the back surface of the printed recording medium, the temperature of the recording medium can be efficiently and quickly reduced,
Even in the high-speed printing process, the ink is not transferred on the discharge roller side, and the image quality does not deteriorate. Further, by providing the suction port and the cooling platen, the distance from the position of the main platen, which is a printing unit, to the paper discharge roller can be reduced, and the printer can be designed to be compact.

According to a third aspect of the present invention, there is provided a hot-melt ink-jet printer which conveys a recording medium along a surface of a main platen facing a nozzle head for ejecting hot-melt ink, and at least supplies the medium to the main platen. The recording medium is supported from the back side while being heated by heating, the hot melt ink is ejected from the nozzle head to the surface of the recording medium to form an image, and then discharged via a discharge roller while being cooled. In the hot-melt ink-jet printer configured as described above, a suction port and a cooling platen are provided on the transport downstream side of the main platen having the main heating means on the back side, and a suction fan arranged on the back side of both platens, The cooling air is introduced from the discharge port side toward the cooling platen.

According to this configuration, the suction fan arranged on the back side of the main platen and the cooling platen causes the cooling air taken in from the sheet discharge port side to be conveyed downstream of the high temperature main platen. As a result of being sucked into the located suction port, heat from the main platen side, which is the leeward side, can cool the cooling platen without heating the cooling air flowing toward the cooling platen, thereby improving the cooling effect. it can. Since the temperature of the recording medium can be efficiently and quickly lowered by contacting the cooling platen with the back surface of the printed recording medium, even if the printing operation is performed at a high speed, the temperature of the paper discharge roller side can be reduced. The ink is not transferred and the image quality is not deteriorated. In addition, by providing the suction port and the cooling platen, the distance from the portion of the main platen, which is a printing unit and in a heated state, to the paper discharge roller can be shortened, and the printer can be designed to be compact. Play.

The invention described in claim 4 is the same as the claim 2
4. The hot melt ink jet printer according to claim 3, wherein the suction port intersects the conveyance path on the upstream side of the cooling platen and conveys, and the first suction port can be closed by a recording medium after printing. On the downstream side of the platen, a second suction port for sucking cooling air is provided on the back side of the cooling platen.

Therefore, in the standby state of the printing operation, the cooling platen can be held at both the first suction port and the second suction port which are not covered by the recording medium so as not to raise the temperature, and the first suction port can be held. The cooling air that is sucked from the mouth can remove the heat of the heated main platen,
The set temperature of the main platen can be rapidly reduced with a change in the type of the recording medium and the printing conditions, thereby also shortening the entire printing processing time. Further, during printing, the cooling platen disposed downstream of the main platen can be maintained at a low temperature mainly by the cooling air from the second suction port, and quickly and rapidly cools the printed high-temperature recording medium. This has the effect that it can be executed efficiently.

According to a fifth aspect of the present invention, in the hot melt ink jet printer according to the fourth aspect, a heat insulating partition is provided at the first suction port so as to separate a main platen and a cooling platen. And it is comprised so that cooling air may pass along both surfaces of this heat insulation partition. With this configuration, heat transfer to the cooling platen side, such as radiant heat from the main platen, which is heated by the main heating means, can be efficiently cut off by the heat insulating partition, and at the time of printing operation standby or the type of recording medium. When changing printing conditions or printing conditions, it is possible to increase the flow rate of cooling air from the first suction port that is not blocked by the recording medium, and quickly change the main platen to a lower set temperature. It also has an effect.

According to a sixth aspect of the present invention, in the hot melt ink jet printer according to any one of the second to fifth aspects, the suction fan is rotated at a high speed during a printing operation, so that the second The cooling platen can be kept at a low temperature by increasing the suction amount of the cooling air from the suction port. On the other hand, when waiting for printing work,
Since it is configured to perform switching operation so as to rotate at low speed, the amount of cooling air sucked at startup is reduced, the heating speed to the main platen is increased, and the time required to reach the set temperature is reduced. This has the effect of reducing the amount of heat taken by the cooling air and reducing the power consumed by the heating means.

According to a seventh aspect of the present invention, in the hot melt ink jet printer according to any one of the second to sixth aspects, the supporting member for supporting the back side of the main platen and the back side of the cooling platen includes: A flow passage for introducing cooling air from the suction port in the suction fan direction is formed. According to this structure, the function of supporting both platens and the function of circulating cooling air can be achieved by one member, and the structure of the printer can be simplified and made compact, and the manufacturing cost can be reduced. To play.

[Brief description of the drawings]

FIG. 1 is a perspective view of a printer.

FIG. 2 is a sectional view of the printer.

FIG. 3 is a schematic plan view illustrating a positional relationship between a carriage, an ink supply unit, and the maintenance operation unit.

FIG. 4 is an enlarged cross-sectional view of a main part of a transport path.

FIG. 5 is a side view of a main platen, a cooling platen, and a support frame.

6A is a sectional view taken along the line VIA-VIA in FIG. 3, FIG.
4 is a sectional view taken along the line VIB-VIB in FIG.

FIG. 7 is a block diagram of a control system.

[Explanation of symbols]

 P Recording medium 1 Printer 5 Paper discharge port 11 Recording head section 12 Carriage 13 Nozzle head 25 Transport roller 26 Main platen 27 Cooling platen 28 Paper discharge roller 29 Transport path 30 Support frame 35 Suction fan 36 First suction port 37 Second Suction port 38 Insulation partition

Claims (7)

[Claims] 1. A recording medium is conveyed along a surface of a main platen facing a nozzle head for ejecting hot melt ink, and the recording medium is supported by the main platen. In a hot melt ink jet printer configured to eject a hot melt ink from the nozzle head to form an image and then cool and discharge the paper via a paper discharge roller, a cooling platen is provided downstream of the main platen in the conveyance direction. A hot-melt inkjet printer characterized by being provided. 2. A recording medium is conveyed along a surface of a main platen facing a nozzle head for ejecting hot melt ink, and the recording medium is supported by the main platen. In a hot melt ink jet printer configured to eject hot melt ink from the nozzle head to form an image by forming an image and then cooling and ejecting the sheet via a sheet ejection roller, a suction port is provided downstream of the main platen for conveyance. A hot-melt inkjet printer, comprising: a cooling platen; and a suction fan disposed on a back side of both platens to introduce cooling air from a sheet discharge port toward the cooling platen. 3. A recording medium is conveyed along a surface of a main platen facing a nozzle head for ejecting hot melt ink, and the recording medium is supported by at least the main platen while heating the recording medium from the back side thereof. A hot-melt ink jet printer configured to eject a hot-melt ink from the nozzle head onto the surface of the recording medium to form an image, and then discharge the paper via a paper-discharge roller while cooling; A suction port and a cooling platen are provided on the downstream side from the main platen provided on the back side, and cooling air is introduced from the sheet discharge port side toward the cooling platen by a suction fan arranged on the back side of both platens. A hot-melt inkjet printer characterized in that it is configured to perform 4. A first suction port which intersects the conveyance path on the upstream side of the cooling platen and which can be closed by a recording medium after printing, and the cooling port on a downstream side of the cooling platen. The second suction port for sucking cooling air on the back side of the platen.
2. The hot melt inkjet printer according to 1. 5. A heat insulating partition which separates the main platen and the cooling platen from each other at the first suction port, so that cooling air can pass along both surfaces of the heat insulating partition. The hot melt inkjet printer according to claim 4, wherein 6. The suction fan according to claim 2, wherein the suction fan rotates at a high speed during a printing operation, and performs a switching operation at a low speed during a printing operation standby. The hot melt inkjet printer as described. 7. A flow path for introducing cooling air from the suction port in the direction of the suction fan is formed in a support member that supports the back side of the main platen and the back side of the cooling platen. The hot melt inkjet printer according to any one of claims 2 to 6.